B) Circulatory.
The Circulatory system spreads the blood all around the heart. It makes sure blood is able to reach every part in the body.
Answer:
the enzyme helps to break down food, the enzyme is in the
saliva. It can break down a big food molecules and divide it into a
simpler food molecules so that it can be digested. . Enzymes are
complex proteins that speed up the rate of chemical reactions.
Answer:
Explanation:
The cell was first discovered by Robert Hooke in 1665 through the microscope. Theodor Schwann and Matthias Jakob Schleiden discovered cell theory and postulated that All living organisms are composed of one or more cells
,the cell is the most basic unit of life and All cells arise only from pre-existing cells
Answer:
the observations that chloroplasts and mitochondria resemble bacteria
Explanation:
The Endosymbiotic Theory is a theory that enables us to understand the origin of eukaryotic cells. The Endosymbiotic Theory posits that the mitochondria and chloroplast, which are organelles found in the eukaryotic cells, were once prokaryotic microbes that were first ingested by amoeba-like organisms and subsequently evolved by developing a symbiotic relationship with them. Some of the most important lines of evidence that supports this theory are: 1-chloroplasts and mitochondria resemble prokaryotic cells, i.e., they have a similar size, replicate by binary fission and there are unicellular eukaryotic protists that have filamentous temperature-sensitive proteins at their division plane (similarly to bacteria), and 2- chloroplasts and mitochondria are organelles with their own DNA and their own ribosomes (which are similar to those of bacteria).